David Deutsch explores the extraordinary nature of human progress, arguing that it is a limitless process fueled by the pursuit of good explanations. He contends that while the scientific revolution marked a unique turning point in history, the true driver of advancement is our ability to conjecture theories rather than simply recording sensory data. By critiquing empiricism and inductivism, the author demonstrates that knowledge is not merely a summary of past experiences but a creative product of the human mind. This intellectual shift allows us to understand vast cosmic phenomena, from the interior of stars to the mechanics of black holes, despite our physical limitations. Ultimately, the source suggests that humanity plays a central role in the universe because our capacity for explanation mirrors the universal laws of nature.